This invention relates to a device for generating a relatively flat, thin, sheet-like stream of air. More particularly, it relates to a grain or seed crop recovery system for harvester machines which utilizes such a sheet-like airstream.
Sheets of moving gas and/or air have been used previously in various commercial and industrial applications. For example, air curtains are commonly used for busy entrances to, and exits from, refrigerated warehouses and air conditioned business or public spaces. In such systems, a "push-pull" arrangement is used with high velocity air supplied through a header and reclaimed in a larger return or suction header.
Heretofore, distribution of the supply air from the header was achieved using an input transition divergent along one axis and convergent along the other. A series of "take-offs" were used with turning vanes, graduated elbows, resistance or equalizing plates, or a combination of these. These relatively complex structures were basically brute force systems with inherent friction factors that caused substantial pressure losses. Such push-pull air curtain systems normally depended on pressure loss to equalize discharge velocities along the length of the discharge slot.
For certain applications, it is not feasible or practical to provide an air-sheet stream using the push-pull type of arrangement, particularly where space considerations for the required apparatus are critical or where it is desired to provide a relatively high velocity stream with an essentially uniform flow rate along an elongated outlet using minimum power consumption. Such a need arose in the harvesting of grain-type crops to provide the solution to the problem of saving grain or seed that might otherwise be lost. Prior to the present invention, substantial amounts of grain or seed-type crops were lost during harvesting because the grain fell to the earth as the grain stalks were first engaged by the harvester reel but before they reached the cutter bar and were moved into the grain collection system. It was discovered that a substantial amount of the grain heretofore lost could be saved by providing a high velocity air stream properly oriented to blow the grain or seeds onto the collector and thereby prevent it from falling on the ground. The blower of the present invention, in combination with a harvester machine, solves this problem.
It is, therefore, one object of the present invention to provide an improved blower device for generating a flat, sheetlike airstream.
Another object of the invention is to provide a blower device that is compact in size and yet capable of producing a relatively high velocity sheet of air or gas but with relatively low input power.
Another object of the invention is to provide a device for producing a sheet-like airstream that is highly efficient yet relatively simple in construction and, therefore, particularly well adapted for ease and economy of construction.
A more specific object of the present invention is to provide a blower device for producing a flat stream of relatively high velocity air from a tubular body which is closed at one end, by supplying the air under pressure to the other open end of the body, forcing it into a spiral flow pattern within the body, and thereafter deflecting it through a flat nozzle portion extending tangentially from the body.
Yet another object of the present invention is to provide a blower in combination with a harvester machine and mounted thereon in such a way that a substantial percentage of the grain or seed from the crop being harvested will be blown onto a recovery mechanism of the harvester and not be lost on the ground.
Another object of the present invention is to provide a flat stream air blower in combination with a harvester machine in a grain recovery system as described, wherein the blower is positioned for maximum efficiency and ease of maintenance.